Date: February 23rd, 2023

Location: San Francisco, CA – Presidio – Batteries to Bluffs Trail

Coordinates: 37.7973617 (North), -122.4793445 (West)

Description: The Battery to Bluffs Trail is a 2.3-mile long hike that loops along the West shore of San Francisco. It has beautiful views of the Pacific Ocean, Baker’s beach, and the Golden Gate Bridge as you walk along the cliffs. The natural life and ecosystem composition found on the trail includes springs, coastal plants, rocky serpentine cliffs, bounties of bright flora, and trees like the Monterey cypress.

Plant Descriptions and Images: 

Family: Apocynaceae, Genus & Species: Vinca major (Vinca)

This species is a perennial evergreen herb characterized by rhizomatous roots, trailing vines, and glabrous leaves that produce a milky juice. Its stems are woody and slender that can spread from 2-5 meters and grow 50-70 centimeters high. Due to its morphology and growth traits, it was introduced to North America as an ornamental plant used for groundcover. The leaves of the vinca are a glossy dark green color with a leathery texture and have entire margins that are distinctly ciliate. Generally, the shape of the leaves range from ovate to ovate-lanceolate and have an opposite formation. Flowers usually bloom in early spring to autumn and are solitary, with up to 4 flowers per stem. They appear bluish-purple in color, have calyx’s that are lobed and ciliate, and have short bristles on their margins.

Family: Fabaceae, Genus & Species: Lupinus chamissonis (Beach blue lupine)

This species is a perennial evergreen shrub characterized by long taproots, legume fruit and silvery stems that are densely hairy. It is a short-lived perennial and sometimes does not bloom until it’s second growth year. The stem of the plant is erect and striated, home to palmately compound leaves organized in an alternating formation. Each leaflet is 10 to 25 millimeters in length, with 5 to 9 leaflets making up one “leaf”. Inflorescences found on the plant have spiky racemes that are 4 to 10 inches tall and possess flowers that are whorled and deciduous. Specifically, each flower has a bract 7 to 10 millimeters in length and present a calyx that is 5 to 7 millimeters on the upper lip and 7 to 9 millimeters on the lower lip. In appearance, the flowers are deeply lobed with entire margins, develop petals that range from light violet to blue in color and have banners that are densely hairy while the keels are variably glabrous. These plants are nitrogen-fixers and work to improve the soil that they are planted in. 

Family: Rosaceae, Genus & Species: Rubus ursinus (California blackberry)

This species is a deciduous perennial shrub characterized by extensive climbing vines, slender stems armed with many bristles, and generally dioecious growing behaviors. Stems of the plant are covered with a white waxy bloom, appear glabrous to hairy, and possess stalked glands at the tips persisting for 2 years. When it comes to the leaves, they are simple or pinnately compound with 3 to 5 leaflets, arranged in an alternate formation, and are sparsely to densely hairy. Margins of the leaves are irregularly coarse-toothed with a triangular-ovate shape at the bottom and acute shape at the top. In the fall, the leaves will change color from dark green to red. Inflorescence patterns of the flowers appear in a cyme formation. The flowers of the plant are generally unisexual with long, slender styles and glabrous to hairy ovaries. Each flower is white in color with an elliptic to round shape and hairy sepals.

iNaturalist Submissions:

1. https://www.inaturalist.org/observations/165089431
2. https://www.inaturalist.org/observations/165089702
3. https://www.inaturalist.org/observations/165089938

Narrative:

The field trip up to the Presidio was my first field experience in the semester. It was colder and cloudy, not making for a very enjoyable day. However, the walk through the trail was beautiful. Since it was technically considered to be the second field trip, my classmates were already able to guess some plant species that I had never heard of. That didn’t bring me down too much though since I was very invested in taking the best notes and making sure my pictures were clear. At the start of our walk, it started to hail really hard. There were some times the professor was not able to explain the plant species to use without getting interrupted by hard hail and our laughter. I also saw a banana slug on the trail, which in addition to the hail, made the field trip really fun. By the end of the field trip, I was really tired as I was out of shape and going up and down hills did not help. Overall though, my first field trip was a great experience.